linux

iv/linux

History

Vladimir Davydov 38d78e587d mqueue: sys_mq_open: do not call mnt_drop_write() if read-only

mnt_drop_write() must be called only if mnt_want_write() succeeded,
otherwise the mnt_writers counter will diverge.

mnt_writers counters are used to check if remounting FS as read-only is
OK, so after an extra mnt_drop_write() call, it would be impossible to
remount mqueue FS as read-only.  Besides, on umount a warning would be
printed like this one:

  =====================================
  [ BUG: bad unlock balance detected! ]
  3.9.0-rc3 #5 Not tainted
  -------------------------------------
  a.out/12486 is trying to release lock (sb_writers) at:
  mnt_drop_write+0x1f/0x30
  but there are no more locks to release!

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2013-03-22 16:41:21 -07:00

compat_mq.c

ipc: initialize structure memory to zero for compat functions

2010-10-27 18:03:13 -07:00

compat.c

selftests: IPC message queue copy feature test

2013-01-04 16:11:45 -08:00

ipc_sysctl.c

ipc: add sysctl to specify desired next object id

2013-01-04 16:11:45 -08:00

ipcns_notifier.c

ipc: do not use a negative value to re-enable msgmni automatic recomputing